Mobile scaffolding brake

ABSTRACT

A mobile scaffolding ( 10 ) for elevating a worker (not shown) above a floor or ground surface (S) is disclosed. The scaffolding ( 10 ) broadly includes a pair of frames ( 12 ) and ( 14 ), a platform ( 16 ) supported by the frames ( 12,14 ), a pair of casters ( 18, 20 ) and ( 22, 24 ) rollably supporting a respective one of the frames ( 12,14 ), and a brake assembly ( 26, 28, 30,  and  32 ) associated with a corresponding one of the casters ( 18,20,22,24 ), respectively. The inventive brake assemblies ( 26,28,30,32 ) enable the worker supported on the platform ( 16 ) to selectively activate and deactivate the respective brake assemblies ( 26,28,30,32 ) from the platform ( 16 ). This enables the worker supported on the platform ( 16 ) to deactivate the brake assemblies ( 26,28,30,32 ), reposition the scaffolding ( 10 ), and then reactivate the brake assemblies ( 26,28,30,32 ) without requiring the worker to dismount from the platform ( 16 ).

RELATED APPLICATION

This is a continuation of application Ser. No. 10/271,634 filed Oct. 15,2002, which is hereby incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to mobile scaffolding. Morespecifically, the present invention concerns a mobile scaffolding brakethat can be activated from the support platform and when activatedrestrains motion of the scaffolding. The inventive brake enables aworker supported on the scaffolding platform to selectively preventunsafe and inadvertent motion of the scaffolding while the worker issupported thereon.

2. Discussion of Prior Art

It is known in the art to utilize scaffolding to provide an elevatedwork platform to elevate a worker above a floor or ground surface tocomplete a task (e.g., painting, drywall finishing, etc.). Thescaffolding utilized to provide the elevated work platform is oftenmobile scaffolding that can be quickly and easily moved from one workingposition to the next. For example, it is known in the art to support ascaffolding frame with one or more casters that enable the assembledscaffolding to be rolled along the floor or ground surface betweenworking positions. However, it is desirable to prevent the scaffoldingfrom moving when one or more workers are supported thereon.

It is known in the art to provide a scaffolding caster with a brake forselectively preventing the scaffolding from moving. These prior artcaster brakes utilize a brake stop that engages the caster wheel andthereby prevents rotation of the wheel. These prior art caster brakestypically include a two-piece housing, with the wheel supported by oneof the housing pieces and the brake stop supported by the other. Thehousing pieces are pivotal relative to one another so that the wheel canbe pivoted into contact with the brake stop. One of the housing piecesserves as a foot-activated handle for selectively causing the wheel tobe pivoted into engagement with the brake stop. In this manner, theweight of the scaffolding supported by the caster works to maintain thelocking engagement between the wheel and the stop.

These prior art caster brakes are problematic and have severalundesirable limitations. For example, the prior art brakes cannot beactivated by a worker while the worker is supported on the scaffoldingplatform. It has been determined that in some applications it isdesirable for a worker supported on the platform to manually repositionthe scaffolding while supported thereon. For example, when using amobile scaffolding to install ceiling tile (e.g., acoustical tile,etc.), OSHA regulations permit the worker supported on the scaffoldingto reposition the scaffolding by pulling it along under the working edgein certain situations. The prior art caster brakes undesirably requirethe worker to either repeatedly climb up and down the scaffolding to setand unset the brake or require two workers (e.g., one to do the tilework on the platform and one to operate the brake from the ground) toperform the same amount of work a single worker could otherwiseaccomplish in the same span of time. It has further been determined thatunsafe working conditions arise when a worker is supported on thescaffolding platform and the brake is not in a locked position (e.g., ifthe tile worker previously described fails to set the brake each time)thereby enabling the scaffolding to roll undesirably placing thesupported worker in peril of losing balance and/or falling off thescaffolding. The supported worker is at the mercy of other coworkers inthe area either setting the brake or refraining from intentionally orunintentionally moving the scaffolding.

SUMMARY OF THE INVENTION

The present invention provides an improved scaffolding brake that doesnot suffer from the problems and limitations of the prior art brakesdetailed above. The inventive brake enables a worker supported on thescaffolding platform to selectively activate the brake while supportedon the support platform to restrain motion of the scaffolding andthereby prevent unsafe and inadvertent motion of the scaffolding whilethe worker is supported thereon.

A first aspect of the present invention concerns a mobile scaffoldingfor elevating a worker above the ground. The scaffolding broadlyincludes a frame, a wheel, a platform, and a brake assembly. The frameis vertically elongated between a first end and a second end. The wheelis coupled to the frame adjacent the first end and is operable torollably support the frame on the ground. The platform is horizontallysupported on the frame and is operable to support the worker above theground. The platform is vertically spaced from the wheel. The brakeassembly is associated with the wheel and includes a brake pad and anactuator in communication with the pad. The brake pad is shiftablerelative to the wheel into and out of a braking position wherein thewheel is generally prevented from rolling. The actuator is selectivelycontrollable by the worker when the worker is supported on the platformto cause the brake pad to shift into and out of the braking position.

A second aspect of the present invention concerns a brake assembly foruse with a mobile scaffolding wherein the scaffolding includes a supportsurface for supporting a worker elevated above the ground. The brakeassembly broadly includes a housing adapted to be coupled to thescaffolding, a handle pivotally coupled to the housing, a brake stopshiftable relative to the housing into and out of a braking positionwherein at least a portion of the stop is configured to engage theground, and an elongated plunger slidable relative to the housing andpresenting a first end coupled to the handle and a second end coupled tothe brake stop.

A third aspect of the present invention concerns a method of braking amobile scaffolding broadly including the steps of moving the scaffoldinginto a working position, positioning a worker on a platform on thescaffolding, and activating a brake from the platform.

A fourth aspect of the present invention concerns a brake assembly foruse with a mobile scaffolding wherein the scaffolding includes a supportsurface for supporting a worker elevated above the ground. The brakeassembly broadly includes a housing adapted to be coupled to thescaffolding, a manual handle pivotally coupled to the housing, a brakestop shiftable relative to the housing into and out of a brakingposition wherein at least a portion of the stop is configured to preventthe scaffolding from moving when the housing is coupled to thescaffolding, and an elongated coupling operably interconnecting thehandle and the brake stop so that the brake stop is remotelycontrollable into and out of the braking position.

Other aspects and advantages of the present invention will be apparentfrom the following detailed description of the preferred embodiments andthe accompanying drawing figures.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

Preferred embodiments of the invention are described in detail belowwith reference to the attached drawing figures, wherein:

FIG. 1 is a perspective view of a mobile scaffolding constructed inaccordance with a preferred embodiment of the present invention andincluding a brake assembly associated with each of the four casters;

FIG. 2 is a fragmentary side elevational view of the scaffolding shownin FIG. 1 illustrating the components of one of the brake assemblies inthe release position;

FIG. 3 is a fragmentary enlarged side elevational view of thescaffolding shown in FIG. 2 with portions of the brake stop shown insection and illustrating the brake assembly in the release position;

FIG. 4 is a fragmentary enlarged side elevational view of thescaffolding similar to FIG. 3 with the brake assembly shown in thebraking position;

FIG. 5 is a fragmentary enlarged side elevational view of thescaffolding taken substantially along line 5-5 of FIG. 2 with the handlesubassembly pivoted to the release position;

FIG. 6 is a fragmentary enlarged side elevational view of thescaffolding similar to FIG. 5 with the handle subassembly shown betweenthe release and braking positions; and

FIG. 7 is a fragmentary enlarged side elevational view of thescaffolding similar to FIG. 6 with the handle subassembly shown in thebraking position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 illustrates a mobile scaffolding 10 constructed in accordancewith a preferred embodiment of the present invention and configured forelevating a worker (not shown) above a floor or ground surface S (seeFIGS. 2-4). The illustrated scaffolding 10 utilizes a pair of rollableladder-type frames to support a vertically-adjustable platformtherebetween. However, the principles of the present invention are notlimited to this scaffolding configuration and equally apply to virtuallyany type of scaffolding so long as the scaffolding supports an elevatedworker and is movable (e.g., rollable, etc.). The illustratedscaffolding 10 broadly includes a pair of frames 12 and 14, a platform16 supported by the frames 12,14, a pair of casters 18, 20 and 22, 24rollably supporting a respective one of the frames 12,14, and a brakeassembly 26, 28, 30, and 32 associated with a corresponding one of thecasters 18,20,22,24, respectively.

In more detail, each of the frames 12,14 is configured to elevate theplatform 16 vertically above the floor or ground surface S and supportthe platform 16 once elevated. The frames 12,14 are virtuallyidentically configured, therefore, only the frame 12 will be describedin detail with the understanding that the frame 14 is similarlyconstructed. The frame 12 includes a pair of spaced apart verticallyextending support posts 34 and 36. Each of the posts 34,36 are generallytubular in configuration presenting a hollow, generally square shapedcross section. For purposes that will subsequently be described, aplurality of spaced apertures 38 are formed in each of the posts 34,36and extend through the respective post 34,36 to form an axially alignedpin-receiving passageway. As will subsequently be described, the lowerends of each of the posts 34,36 are open and configured to receivevarious attachment components, such as one of the casters 18,20,22,24.Formed in the upper end of each of the posts 34,36 is a correspondingcoupling shaft 40 and 42, respectively. Each of the shafts 40,42 isconfigured to removably receive various attachment components, such asguard rails, another frame member, etc. Fixed to each of the posts 34,36and extending horizontally therebetween, are a plurality of rung members44, 46, 48, 50, and 52. The rungs 44,46,48,50,52 are spaced from oneanother and configured to enable the worker to climb up and down therungs (e.g., in order to reach and exit the platform 16). The frame 12defines a first, lower end 54 adjacent the rung 44 and a second, upperend 56 adjacent the rung 52 (see FIGS. 1-2).

One exemplary frame is disclosed in pending application for U.S. patentSer. No. 09/766,334, filed Jan. 19, 2001, entitled UTILITY SCAFFOLDINGHAVING SAFETY FEATURES (sharing a common inventor with the presentapplication and hereinafter “the Wyse '334 application”), which ishereby incorporated by reference herein as is necessary for a full andcomplete understanding of the present invention. However, the framecould be variously constructed and configured. For example, the frameneed not utilize a tubular construction and need not be a ladder-typeframe.

The platform 16 is supported horizontally between the frames 12 and 14and is vertically adjustable between the upper and lower ends of theframes 12,14. Particularly, the platform 16 includes a pair ofhorizontally extending side rails 58 and 60 that support a generallyflat work surface 62. The illustrated work surface 62 is removablycoupled to the rails 58,60 by a plurality of transverse pins 64.Although not shown, the platform 16 preferably includes rail pins andplatform clips that can be pivoted into a locking position once thesurface 62 is placed on the rails 58,60 to prevent the surface 62 fromdislodging from the pins 64. Exemplary rail pins and clips are disclosedin the Wyse '334 application, previously incorporated herein byreference. The illustrated platform 16 further includes a pair ofbracket assemblies 66, 68 and 70, 72 associated with each of the frames12,14, respectively. The paired bracket assemblies 66,68 and 70,72include assemblies that are mirror images of each other, but otherwiseeach of the assemblies 66,68,70,72 are virtually identically configuredand therefore only the bracket assembly 66 will be described in detailwith the understanding that the assemblies 68,70,72 are similarlyconstructed. The bracket assembly 66 includes a sleeve 74 slidablyreceived on the post 34 of the frame 12. The sleeve 74 is generallyC-shaped in cross section to define an open side configured to clear therungs 44,46,48,50,52 as the sleeve slides relative to the frame 12. Thesleeve 74 includes a plurality of apertures formed on the inside surfacethat are complementally spaced to match the spacing of the apertures 38formed in the post 34 (not shown on the assembly 66, but see the bracketassembly 70). In this manner, the sleeve apertures are operable toaxially align with the post apertures 38. In this regard, the bracketassembly 66 further includes a G-shaped pin 76 that is slidably receivedin the axially aligned apertures to retain the platform 16 in a selectedvertical position relative to the frame 12. The G-shaped pin 76preferably slides in a pin guide 78 and is biased into the aligned holesby a spring (not shown). Although not shown, the bracket assembly 66preferably includes an additional locking pin slidably received in asecond set of axially aligned apertures to lock the platform 16 in theselected vertical position. It is within the ambit of the presentinvention to utilize various alternative locking mechanisms andexemplary pin-type mechanisms are disclosed in the Wyse '334 applicationpreviously incorporated herein.

The sleeve 74 is fixed to the rail 58 by a block 80 and by a gusset 82.In this manner, the rail 58, and thus the work surface 62 supportedthereon, slides with the sleeve 74 relative to the frame 12. The block80 is open on its upper end and includes means for securing attachmentcomponents in the block 80 (e.g., the illustrated block 80 is configuredto receive a guard rail (not shown) and includes a pin-receivingaperture to removably secure the guard rail in the block 80). The gusset82 provides additional support to the rail 58 relative to the sleeve 74.

One exemplary platform is disclosed in the previously incorporated Wyse'334 application. However, the platform could be variously constructedand configured, for example, the platform need not be adjustable, andcould be fixedly supported along the frames, or on top of the frames.

The illustrated scaffolding 10 is a mobile scaffolding. In more detail,each of the frames 12,14 are supported by a corresponding pair of thecasters 18,20 and 22,24, respectively. Each of the casters 18,20,22,24are virtually identically configured and therefore only the caster 18will be described in detail with the understanding that the casters20,22,24 are similarly constructed. The caster 18 is swively received inthe open lower end of the post 34 of the frame 12. In one manner knownin the art, the caster 18 includes a caster housing 84, a stub shaft 86swively coupled to the housing 84, and a wheel 88 rollably supported inthe housing 84. The caster housing 84 supports the post 34 on the wheel88. The stub shaft 86 is removably received in the open lower end of thepost 34 and is configured to be locked in the post 34. For example, theillustrated shaft 86 includes an aperture (not shown) that aligns withthe lower-most pin-receiving passageway formed by the bottom apertures38 in the post 34. In this manner, a retaining pin (not shown) can beinserted through the post 34 and the stub shaft 86 to retain the shaftin the lower end of the post 34. The stub shaft 86 includes a bearingring formed in its lower end that carries a bearing (not shown) to allowthe caster housing 84 and thus the wheel 88 to swivel relative to thestub shaft 86 while still supporting the weight of the frame 12 and theplatform 16 carried by the post 34. The wheel 88 is axled to the housing84 so that the wheel 88 is free to roll relative thereto. In thismanner, the casters 18,20,22,24 cooperate to provide mobility to thescaffolding 10. It is within the ambit of the present invention toutilize various alternatively configured means for providing mobility tothe scaffolding 10. However, it is important that the scaffolding beenabled to move relative to the supporting floor or ground surface S.

The mobile scaffolding 10 can be prevented from moving relative to thesupporting floor or ground surface S by the brake assemblies 26,28,30,32associated with each of the casters 18,20,22,24. The inventive brakeassemblies 26,28,30,32 enable the worker to select and control when themobile scaffolding 10 is prevented from moving while the worker iselevated on the platform 16. Each of the brake assemblies 26,28,30,32are virtually identically configured and therefore only the brakeassembly 26 will be described in detail with the understanding that thebrake assemblies 28,30,32 are similarly constructed. The illustratedbrake assembly 28 includes a lower brake housing 90, an upper brakehousing 92, a brake stop subassembly 94, a plunger 96, and a handlesubassembly 98 (see FIGS. 1-2). In more detail, and as shown in FIGS.3-4, the lower brake housing 90 includes a bracket 100 that is coupledto the lower end of the post 34 of the frame 12 adjacent the caster 18.The illustrated bracket 100 is bolted to the post 34 through a pair ofthe pin-receiving passageways formed by the aligned apertures 38 in thepost 34. The lower brake housing 90 further includes a transverse bar102 fixed to the bracket 100 and extending generally orthogonallytherefrom. For purposes that will described below, the bar 102 isdimensioned and configured so that its distal end (the end opposite thebracket 100) extends over and sufficiently past the wheel 88 of thecaster 18. For purposes that will subsequently be described, the lowerbrake housing 90 includes a tubular sleeve 104 fixed to the distal endof the transverse bar 102. The illustrated sleeve 104 extends generallyparallel to the post 34 of the frame 12 and is open along its entireaxial length and at both its upper and lower ends. For purposes thatwill subsequently be described, the sleeve 104 includes a vertical slot104 a formed in the tubular wall of the sleeve 104 and configured toslidably receive a pin or bolt so that the pin and/or bolt received inthe slot 104 a passes through the sleeve 104 and extends out of thetubular wall of the sleeve 104 at diametrically opposite locations. Aswill be described below, the lower brake housing 90 further includes afulcrum post 106 fixed to and extending upwardly from the transverse bar102. The fulcrum post 106 is spaced from the sleeve 104 and positionedbetween the bracket 100 and the sleeve 104.

The upper brake housing 92 is coupled to the upper end of the post 34 ofthe frame 12 and includes a bracket 108 and a bushing block 110. Theillustrated bracket 108, similar to the bracket 100, is bolted to thepost 34 through a pair of the pin-receiving passageways formed by thealigned apertures 38 in the post 34. The bracket 108 includes a portion108 a that extends generally transversely from the post 34 and includesan opening (not shown). The bushing block 110 is fixed to the bracketportion 108 a. In the illustrated upper brake housing 92, the bushingblock includes a section that extends through the opening in the bracketportion 108 a and includes external threads that receive a bushing blocknut 110 a to couple the bushing block 110 to the bracket portion 108 a.As will be subsequently described, the bushing block 110 is configuredto slidably receive at least a portion of the plunger 96.

The lower and upper brake housings 90,92 are removably couplable to theframe 12. In this regard, the brake assembly 26 can be easily added on,or coupled to, existing scaffolding. However, it is within the ambit ofthe present invention to utilize various alternative configurations forthe brake housings 90,92. For example, the housings could be integrallyformed with the scaffolding frame during the original manufacturethereof.

The brake stop subassembly 94 is shiftably coupled to the lower brakehousing 90 and is shiftable between a braking position as shown in FIG.4, wherein the wheel 88 of the caster 18 is generally prevented frommoving relative to the floor or ground support surface S, and a releaseposition as shown in FIG. 3, wherein the wheel 88 is free to move.Particularly, the brake stop subassembly 94 includes a pivot bar 112, anupper tube 114, a lower shaft 116, and a brake stop 118. The pivot bar112 presents a proximate end 112 a generally adjacent the post 34 of theframe 12, and an opposite, distal end 112 b spaced from the proximateend 112 a. The pivot bar 112 is pivotally coupled to the fulcrum post106 of the lower brake housing 90 generally between the ends 112 a,b ofthe pivot bar 112. The illustrated pivot bar 112 presents a pair of sidepanels, spaced apart by a cross bar 112 c, that straddle the fulcrumpost 106 and are bolted together through the post 106. When the brakestop subassembly 94 is in the release position, the pivot bar 112 isgenerally parallel to the transverse bar 102 of the lower brake housing90 (see FIG. 3). When the brake stop subassembly 94 is in the brakingposition, the proximate end 112 a of the pivot bar 112 is further spacedfrom the transverse bar 102 and the distal end 112 b is closer to thetransverse bar 102 (see FIG. 4). For purposes that will subsequently bedescribed, formed in the distal end 112 b of the pivot bar 112 is alongitudinally extending bolt-receiving slot 112 d.

The upper tube 114 of the brake stop subassembly 94 is slidably receivedwithin the sleeve 104 of the lower brake housing 90. The upper tube 114includes three pins fixed relative to the tube 114 and extendingdiametrically through the center of the tube 114, an upper pin 120, anintermediate pin 122, and a lower pin 124. The upper end of the tube 114is received between the side panels of the pivot bar 112 and the upperpin 120 extends through the upper end of the tube 114 so that it isslidably received within the bolt-receiving slot 112 d of the pivot bar112. In this manner, when the pivot bar 112 pivots, the movement of thedistal end 112 b causes the upper tube 114 to slide relative to thesleeve 104. For purposes that will subsequently be described, theintermediate pin 122 extends through the tube 114 and is positioned sothat it is slidably received in the vertical slot 104 a of the sleeve104. As will subsequently be described, the lower pin 124 is positionedadjacent the lower end of the tube 114. The lower pin 124 need notnecessarily extend through the outer wall of the tube 114. However, aswill become apparent below, for assembly purposes, the lower pin 124 ispreferably inserted after the lower tube 116 is slidably received insidethe upper tube 114 (e.g., spring-biased and/or detented against theinside wall of the sleeve 104, etc.).

The lower shaft 116 is slidably received within the lower end of theupper tube 114 so that the lower end of the shaft 116 extends out of thelower end of the upper tube 114. Particularly, the lower shaft 116includes a horizontal slot 116 a formed in its wall that is configuredto slidably receive the lower pin 124 of the upper tube 114. In thismanner, the lower shaft 116 has a limited range of slidable motionrelative to the upper tube 114, yet still is caused to generally shiftrelative to the sleeve 104 when the upper tube 114 shifts relative tothe sleeve 104. The lower shaft 116 slides relative to the upper tube114 between an extended position as shown in FIG. 3, wherein the shaft116 is extends out of the upper tube 114 until the top of the slot 116 aengages the lower pin 124 of the upper tube 114, and a retractedposition as shown in FIG. 4, wherein the shaft 116 retracts into theupper tube 114 until the bottom of the slot 116 a engages the lower pin124 of the upper tube 114. The lower shaft 116 is spring biased into theextended position by a spring 126. The top end of the spring 126 ridesagainst the intermediate pin 122 of the upper tube 114 and the lower endof the spring 126 rides against the upper end of the shaft 116. In thismanner, the spring force of the spring 126 must be overcome to cause theshaft 116 to slide into the retracted position as shown in FIG. 4. Forpurposes that will be described below, the lower end of the shaft 116includes internal threading.

The brake stop 118 is fixed to the lower end of the shaft 116 and thusis caused to move with the shaft 116. The stop 118 includes a threadedshaft 128 and a disk 130. The upper end of the threaded shaft 128threads into the internal threads of the lower end of the shaft 116 andthe lower end of the threaded shaft 128 is coupled to the disk 130. Theillustrated stop 118 includes locking nuts 132 so that the position ofthe stop 118 relative to the lower shaft 116 can be adjusted and lockedinto the desired position once adjusted. The disk 130 presents arelatively flat bottom surface that engages the floor or ground supportsurface S when the brake stop subassembly 94 is in the braking position(see FIG. 4) and is spaced from the floor or ground surface S when thesubassembly 94 is in the release position (see FIG. 3). The engagementbetween the disk 130 and the floor or ground surface S prevents thewheel 88 of the caster 18 from moving relative thereto. Accordingly, thedisk must be sufficiently strong to withstand engagement with thesurface S and the bottom surface of the disk 130 is preferably formedfrom a material having gripping properties such as various plasticpolymers, rubber, etc. The illustrated disk 130 is formed from metal(e.g., steel, aluminum, etc.) and covered with an industrial gradesofter rubber. The range of motion provided between the extended andretracted positions of the lower shaft 116 enables the disk 130 togrippingly engage a floor or ground surface that is not uniformly even.However, the disk 130 preferably is pivotal relative to the threadedshaft 128 (e.g., coupled thereto with a ball joint, etc.) to facilitategripping engagement of uneven support surfaces. Additionally, the springforce of the spring 126 facilitates the gripping engagement of the disk130 with the floor or ground surface S.

The plunger 96 extends between the lower and upper brake housings 90,92and transfers movement of the handle subassembly 98 to the brake stopsubassembly 94. In this regard, the illustrated plunger 96 is a rigidrod presenting a bottom end 96 a and an opposite, spaced top end 96 b.The bottom end 96 a is pivotally coupled to the proximate end 112 a ofthe pivot bar 112 of the brake stop subassembly 94. The bottom end 96 aof the illustrated plunger 96 includes a collar 96 c that is receivedbetween the side panels of the pivot bar 112 and rotatably receives abolt 132 coupled to the panels of the bar 112 (see FIGS. 3 and 4). Thetop end 96 b is slidably received through the bushing block 110 of theupper brake housing 92. The top end 96 b of the illustrated plunger 96includes a stub shaft 96 d that is dimensioned and configured to slidewithin the opening of the bushing block 110 and extend out of the topand bottom of the bushing block 110. In this manner, the stub shaft 96 dcan be formed from a strong durable material that can be machined to thedesired size (e.g., steel, etc.) while the other portions of the plunger96 can be formed from a relatively cheaper, light weight material (e.g.,various plastic polymers, etc.).

Turning to FIGS. 5-7, the handle subassembly 98 is coupled to the upperbrake housing 92 and enables a worker supported on the scaffolding 10 toshift the brake stop subassembly 94 into and out of the braking positionto selectively prevent movement of the scaffolding 10. In more detail,the handle subassembly 98 includes a handle 134 and a guide bracket 136.The handle 134 is generally L-shaped and presents a grip 134 a at oneend and a coupling fork 134 b that elbows out of the opposing end. Thecoupling fork 134 b is pivotally coupled to the top end portion of thestub shaft 96 d of the plunger 96 that extends out of the top of thebushing block 110. The guide bracket 136 is pivotally coupled to theelbow of the handle 134 at one end and pivotally coupled to the bushingblock 110 at the opposite end. The handle 134 is pivotal from theposition shown in FIG. 5, wherein the grip 134 a is oriented toward thepost 36 of the frame 12 and somewhat parallel to the rung 52 of theframe 12, to the position shown in FIG. 7, wherein the grip 134 a isoriented away from the post 36 and somewhat parallel with the rung 52,with the position shown in FIG. 6 being the intermediate, centerposition, wherein the grip 134 a is not at all parallel with the rung52. When the handle 134 is in the position shown in FIG. 5, the top end96 b of the plunger 96 is adjacent the bushing block 110 correspondingto the brake stop subassembly 94 being in the release position as shownin FIG. 3. As the handle 134 is pivoted toward the center position shownin FIG. 6, the weight of the plunger 96 must be overcome and the top end96 b of the plunger 96 is caused to slide up and away from the top ofthe bushing block 110. As the fork 134 b pivots relative to the plungerend 96 b, the elbow of the handle 134 pivots relative to the guidebracket 136. In this manner, the handle subassembly 98 transfers onlystraight-line motion to the plunger 96. As the handle 134 is pivotedpast the center position shown in FIG. 6, the handle 134 is urged intothe position shown in FIG. 7. When the handle 134 is in the positionshown in FIG. 7, the top end 96 b of the plunger 96 is spaced upwardlyfrom the top of the bushing block 110 corresponding to the brake stopsubassembly 94 being in the braking position as shown in FIG. 4. Theweight of the plunger 96 and the configuration of the handle subassembly98 cooperate to maintain the handle 134 in the position shown in FIG. 7.In order to pivot the handle 134 back into the position shown in FIG. 5,the weight of the plunger 96 must again be overcome until the handle 134pivots past the center position shown in FIG. 6. Once the handle 134pivots past the center position, the weight of the plunger 96 urges thehandle 134 back into the position shown in FIG. 5 and maintains thehandle 134 in that position. In this regard, the illustrated handlesubassembly 98 is a straight-line over-the-center-type clamp. One suchsuitable clamp is available from DE-STA-CO Industries of MadisonHeights, Mich. as Model No. 604.

As previously indicated, the braking assemblies 28,30,32 are virtuallyidentically configured as the braking assembly 26. However, it is withinthe ambit of the present invention to utilize a single braking assembly,or the inventive braking assembly in combination with traditional casterbrakes, as well as various alternatively configured braking assemblies.For example, the brake assembly need not utilize a brake stop thatengages the ground to prevent movement of the scaffolding, but rathercould implement traditional-type brake stops that engage the wheel toprevent movement. Additionally, the brake assembly need not utilize apivotal handle or a rigid plunger to activate the brake stop. Forexample, the brake assembly could utilize an electronically activatedbrake stop with a remotely located controller, or hard wire linkage.However, it is important that the brake stop be capable of activation bythe worker while the worker is supported on the scaffolding in order toprevent movement of the scaffolding.

In operation, the scaffolding 10 is assembled and rolled into thedesired work position on the supporting floor or ground. The worker thenmounts the scaffolding 10 (e.g., by climbing up the rungs44,46,48,50,52) so that the worker is supported on the platform 16. Inorder to activate the braking assembly 26, the worker grasps the grip134 a of the handle 134 and pivots the handle 134 from the positionshown in FIG. 5 to the position shown in FIG. 7. As the handle 134 ispivoted, the plunger 96 is pulled upward. As the plunger 96 is pulledupward, the brake stop subassembly 94 is caused to shift from therelease position shown in FIG. 3 to the braking position shown in FIG.4. The braking assemblies 28,30,32 can be similarly activated. Themobile scaffolding 10 is now prevented from moving and the worker issecurely supported on the platform 16 for safe working. If the workerdesires to deactivate one or more of the braking assemblies, the abovedescribed steps are simply reversed. Once the braking assemblies aredeactivated, the mobile scaffolding 10 can be rolled to the next desiredwork position (e.g., the supported worker can pull the scaffolding 10along the supporting surface S). Once the scaffolding 10 isrepositioned, the worker can reactivate the braking assemblies from theplatform 16.

The preferred forms of the invention described above are to be used asillustration only, and should not be utilized in a limiting sense ininterpreting the scope of the present invention. Obvious modificationsto the exemplary embodiments, as hereinabove set forth, could be readilymade by those skilled in the art without departing from the spirit ofthe present invention.

The inventors hereby state their intent to rely on the Doctrine ofEquivalents to determine and assess the reasonably fair scope of thepresent invention as pertains to any apparatus not materially departingfrom but outside the literal scope of the invention as set forth in thefollowing claims.

1. A mobile scaffolding for elevating a worker above the ground, saidscaffolding comprising: a frame; a plurality of wheels supporting theframe for rolling movement on the ground; a platform supported on theframe and being operable to support the worker above the ground, saidplatform being spaced above the ground; and a brake assembly configuredto selectively prevent rolling movement of the frame, said brakeassembly including an actuator that causes the brake assembly to preventrolling movement of the frame when the actuator is engaged and permitrolling movement of the frame when the actuator is disengaged, at leasta portion of said actuator being positioned above the platform to enablethe worker to control engagement and disengagement of the actuator fromthe platform when supported thereon.
 2. The scaffolding as claimed inclaim 1, said frame being vertically elongated between a first end and asecond end, said at least a portion of said actuator being verticallypositioned between the platform and the second end of the frame.
 3. Thescaffolding as claimed in claim 1, said actuator including a handlepivotal relative to the frame.
 4. The scaffolding as claimed in claim 3,said frame being vertically elongated between a first end and a secondend, said handle being positioned adjacent the second end of the frame.5. The scaffolding as claimed in claim 3, said brake assembly furtherincluding an elongated plunger slidable relative to the frame andpresenting a proximate end adjacent the handle and a distal end adjacentone of said plurality of wheels.
 6. The scaffolding as claimed in claim5, said handle being coupled to the proximate end of the plunger so thatpivoting of the handle causes the plunger to slide relative to theframe.
 7. The scaffolding as claimed in claim 6, said brake assemblyincluding a brake pad, said brake pad being coupled to the distal end ofthe plunger so that sliding of the plunger relative to the frame causesthe pad to shift into and out of a braking position, wherein said brakepad engages the ground.
 8. The scaffolding as claimed in claim 1, saidbrake assembly including a brake pad, said brake pad including agenerally flat disc that engages the ground when the brake pad is in abraking position, wherein said brake pad engages the ground.
 9. A methodof braking a mobile scaffolding, said method comprising the steps of:(a) moving the scaffolding into a working position; (b) occupying theplatform; and (c) activating a brake to prevent movement of thescaffolding, step (c) including the step of engaging an actuator of thebrake from the platform so as to activate the brake, wherein at least aportion of the actuator is positioned above the platform.
 10. The methodas claimed in claim 9, step (c) including the step of manually operatinga handle, comprising said at least a portion of the actuator, to controlengagement of the actuator.
 11. The method as claimed in claim 10, step(c) including the step of pivoting the handle to engage and disengagethe actuator.
 12. The method as claimed in claim 9, step (c) beingperformed after step (b).
 13. The method as claimed in claim 12; and (d)deactivating the brake, repositioning the scaffolding, and reactivatingthe brake once the scaffolding is repositioned, step (d) being performedafter step (c) and while the platform is occupied.
 14. The method asclaimed in claim 9, step (c) including the step of shifting a brake padinto engagement with the ground when the actuator is engaged.